The present invention disclosed herein relates to a support unit and an apparatus for treating a substrate, and more particularly, to a support unit using plasma and an apparatus for treating a substrate.
To manufacture semiconductor devices, various processes such as photolithography, etching, ashing, ion-injection, thin film deposition, and cleaning may be performed on a substrate to form a desired pattern on the substrate. Among these processes, the etching process is a process for removing a heated area selected from a layer formed on the substrate. The etching process may include wet etching and dry etching.
Here, an etching device using plasma may be used for the dry etching. In general, electromagnetic fields may be formed in an inner space of a chamber to form plasma. The electromagnetic fields may excite a process gas provided into the chamber into a plasma state.
Plasma represents an ionized gas containing ions, electrons, and radicals. The plasma may be generated by a very high temperature, strong electric fields, or high-frequency electromagnetic fields (EF). In a process for manufacturing the semiconductor device, the etching process is performed using the plasma. Ion particles contained in plasma collide with a substrate to perform the etching process.
Generally, a sensor for detecting a supported state of the substrate is provided on a support unit. However, since the sensor is disposed on a central portion of the support unit, it is difficult to determine whether the substrate is properly supported. Also, the sensor may not detect a state of the whole substrate, e.g., a case in which the substrate is broken.